ERA - Jag rearend

Todd Hedges · #1 (**permalink**) 07-12-2002, 08:05 AM

Bob

I know a typical limited slip will make noise when turning, however how loud is the "clunk" noise when the diff. locks up? When making a tight turn at low speeds I hear and fell it, even over the side pipe sound. Is it typical for the noise to be that noticeable and to "clunk" two or three times in one turn? It doesn't happen every single time, but when it does, it makes you wonder what's happening.

Thanks
Todd

Todd

Jeff Frigo · #2 (**permalink**) 07-12-2002, 10:22 AM

Sounds like a U-joint.

Bob Putnam · #3 (**permalink**) 07-12-2002, 12:35 PM

Some of the LSDs are stickier than others. From your manual:

Differential: Fill with Moroso climbing gear lube, SAE 90, part number 34800. Mix with 4 to 8 oz. of Amalie limited slip additive (part # 505-6775). If the above are not available, you may use 80W-90 GL5 lubricant with an equivalent limited slip additive. If the limited slip seems to be sticking (ratcheting around sharp corners), replace the Amalie additive with 2 tubes of GM additive 1052358.

Todd Hedges · #4 (**permalink**) 07-18-2002, 05:54 AM

Bob,

I think Jeff Frigo is correct. The noise has become much worse, and the diff. lube didn't solve it. I will have to take the car off the road and check the U-joints on the axels. Seems odd that one would fail with less than 4500 miles on the car. Is there something else I should look for while the car is out of commission?

Thanks.

p.s. Bob, if it is a u-joint on the axel, how difficult is the replacement? (intermediate mechanical skills w/average tools).
Are the joints readily available?

Todd

Todd Hedges · #5 (**permalink**) 07-19-2002, 05:27 AM

The condition where the rear axel makes a loud clunk noise happens only of left turns. It happens 3 or 4 times, then once the car is straight, no more noise. Any ideas?

Tom Kirkham · #6 (**permalink**) 07-19-2002, 08:18 AM

You may also want to check the spider gears in the diff. We had the same problem with CSX3104 where the car would shake and pop when turning. In our diffs we use Fords friction modifier.

Todd Hedges · #7 (**permalink**) 07-19-2002, 08:40 AM

Thanks Tom.

What was the solution for CSX3104?
Did the modifier solve it, of did the spider gears require shims/alignment?

John 550 · #8 (**permalink**) 07-19-2002, 02:35 PM

Todd , Put in the two tubes of GM additive , see if that does it . If not , then drop the cover and check for spider teeth in the bottom of ham . If it's the spider gears , you will appreciate the sub frame .

Tom Kirkham · #9 (**permalink**) 07-20-2002, 09:37 PM

We had to replace the spider gears and the cross shafts. The Dana 44 Power Lock came in two versions, one with two spider gears and the other with 4 spider gears. The 4 spider gear version is much stronger. The orginal cobras came with 4 spider gears. If you have the two spider gear version I would suggest upgrading to the 4 version or better yet to a Quaiffe. The only bad part about a Quaiffe is the price (about $1,500), however they work great. I am afraid that it is time for you to pull the cover off your diff and look inside and see what is laying in the bottom. At the very least I would drain the fluid and see how much "metal" is in the oil. Good luck
Tom

Todd Hedges · #10 (**permalink**) 07-22-2002, 10:12 AM

I put in 8 ounces of friction modifier (Mix with 4 to 8 oz. of Amalie limited slip additive (part # 505-6775). It appears to have corrected the problem to a certain extent. I was only able to drive a short time on Saturday. Out of the 17 - 1st gear left turns, I heard the noise only once. I'm not sure if it was a result of the gear oil not getting hot yet, or if it is because the modifier worked. Still looking forward to Bob's input once back from Vac.

Bob,
Which diff. are used in the ERA Custom assembly? (See Tom K. reply - 2 or 4 spider gears)

Thanks
Todd

Bob Putnam · #11 (**permalink**) 07-23-2002, 05:26 AM

Doug is out until Tuesday - he's the only one who is privy to the differential innards. I'll fiind out soon...

We've had very few spider gear failures that I know about.

Jerry Chabino · #12 (**permalink**) 07-23-2002, 06:28 AM

While on this subject can U guys fill me in on where the oil filler plug is on the Jag, and what is the proper way to check the oil level.
Tnx,

Jerry

Todd Hedges · #13 (**permalink**) 07-23-2002, 06:35 AM

It's in the back cover of the "meatball" about 1/2 way up - between the differential and the gas tank. Fill till it just starts to get even with the fill hole. The best way to fill it is with a flexible piece of 3/8" or 1/2" tubing and a squeeze bottle. not a lot of room there to stuff a container of gear oil to try and fill it directly.

Jerry Chabino · #14 (**permalink**) 07-23-2002, 10:30 AM

Thanks for the info Todd.

Bob Putnam · #15 (**permalink**) 07-23-2002, 12:23 PM

The official Doug-skinny is that all the difs we get from Reider Racing (and that's every rear we build) have 4 spiders.

Todd Hedges · #16 (**permalink**) 07-26-2002, 02:39 PM

Thanks Bob,
That helps put the mind at ease, and should sell more
Custom ERA units.

Todd Hedges · #17 (**permalink**) 07-27-2002, 06:26 AM

The friction modifier worked.
Originally I had used a Redline oil limited slip modifier.
The amalie did the trick.
No more noises.

Now I have to find a way to get some driver training and tryout life on a track.